{"id":"CVE-2026-49476","aliases":["GHSA-2wc2-fm75-p42x","PYSEC-2026-3071"],"url":"https://o3.security/vulnerability/CVE-2026-49476","summary":"Soup Sieve: Memory Exhaustion via Large Comma-Separated Selector Lists in soupsieve","details":"Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve allocates unbounded memory when compiling large comma-separated selector lists, allowing an attacker who can supply a crafted selector string to soupsieve.compile() or Beautiful Soup .select() / .select_one() to allocate hundreds of megabytes of heap memory from a relatively small input and cause denial of service. This issue is fixed in version 2.8.4.","published":"2026-07-14T20:53:12.497Z","modified":"2026-08-12T03:51:30.645530585Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00522,"percentile":0.42051,"asOf":"2026-08-29"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"soupsieve","fixedVersion":"2.8.4"}],"fix":{"url":"https://github.com/facelessuser/soupsieve/commit/28108ab805818c832d9568142a99844fd95a0d39","label":"facelessuser/soupsieve@28108ab"},"references":[{"type":"WEB","url":"https://github.com/facelessuser/soupsieve/releases/tag/2.8.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49476.json"},{"type":"ADVISORY","url":"https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49476"},{"type":"FIX","url":"https://github.com/facelessuser/soupsieve/commit/28108ab805818c832d9568142a99844fd95a0d39"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:30.645530585Z"}}